PRAGUE, Czech Republic - Italian lucky loser Jasmine Paolini won her second career WTA main draw match on Tuesday, upsetting No.3 seed Daria Kasatkina, 7-6(6), 6-3 at the J&T Banka Prague Open.

"It's incredible, biggest win of my career," Paolini said after the match. "I had to stay focused in the end as I saw she was injured. I knew I had to keep the level of my play and stay focused."

Kasatkina was coming off a first round loss at the Porsche Tennis Grand Prix, and those struggles continued against Paolini, who won two matches in qualifying before falling to Antonia Lottner in the final round on Monday.

"It’s surprising because I’d lost but got in as a lucky loser. I knew today would be a very tough match but I tried to play my game and it worked, so I’m very happy."

Paolini won her maiden WTA main draw match just a few weeks ago at the Claro Open Colsanitas, and showed impressive maturity even as the Russian teenager fought back from a set and 3-1 down, winning the final three games as Kasatkina struggled with a left thigh injury - one that required a off-court medical timeout.

"I stayed close to the line so I could push every ball, tried not to rush but take the ball early and play my game."

Up next for the 22-year-old is Claro Open Colsanitas champion Anna Karolina Schmiedlova, who won her first title in nearly two years in Bogota to return to the Top 100.

"I like this tournament a lot. The city, the courts, the balls, people. I am really having good time here."

Around the grounds, Kristyna Pliskova upset No.9 seed Aliaksandra Sasnovich, 7-6(5), 6-3; Pliskova had been set to play twin sister Karolina before the Porsche Tennis Grand Prix champion withdrew due to a right thigh injury.

Qualifier Antonia Lottner, who beat Paolini in qualifying, also had success on Tuesday, upsetting former Prague champion Mona Barthel, 6-0, 7-5, while No.7 seed Mihaela Buzarnescu edged past Beatriz Haddad Maia, 6-1, 7-5.

Denisa Allertova saw past former World No.8 Patty Schnyder, 6-4, 6-4, and Camila Giorgi put on a stunning display to hand No.5 seed Barbora Strycova her sixth straight singles loss, 6-0, 2-6, 6-2.